Proton-Electron Dual-Transfer-Channel Nanoreactors for Proton-Coupled Electron Transfer (PCET) in Photocatalytic Polyester Dehydrogenation-Reductive Amination

Abstract

The photocatalytic polyester-to-amino acid transformation is significant for waste upcycling, yet challenging owing to the intricate multiple proton and electron transfer processes required. Herein, a general strategy for synthesizing hollow core-shell Sv-chalcogenide/Ti₃C₂ nanoreactors (Sv = sulfur vacancies, chalcogenide = CdS/ZnIn₂S₄/CdIn₂S₄) is developed via templated epitaxial growth and defect-mediated interfacial bond construction, which act as the strong proton/electron extractor and relay station for tandem proton-coupled electron transfer (PCET) in photocatalytic polyester-to-amino acid dehydrogenation-reductive amination. These nanoreactors integrate spatially segregated proton-electron dual-transfer channels, where the interfacial asymmetrical charge distribution-induced built-in electric field (BIEF) drives directional electron transfer (ET) from chalcogenide to Ti₃C₂, while the electron-rich interfacial lattice oxygen mediates substrate deprotonation process via nucleophilic abstraction, delivering protons to Ti₃C₂ and forming Ti₃C₂(OH)⁺ intermediates to trigger proton transfer (PT). By virtue of dynamically optimized molecular catalytic behavior accomplished through precise regulation of pivotal intermediate adsorption and activation energetics, the representative Sv-CdS/Ti₃C₂ hollow nanoreactor (HNR) exhibits remarkable performance (10 mmol·g⁻¹·h⁻¹ and 91% selectivity, alanine) and broad applicability for polyester-derived hydroxy acid-to-amino acid transformation. This study establishes a pioneering paradigm for the design of proton-electron dual-transfer-channel photocatalysts and provides novel perspectives for the effective regulation of complex reaction pathways.